| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive adaptive overcurrent detecting cutout element allowing an overcurrent detection level to be set arbitrarily from the outside or by a electric potential at both ends of the element. SOLUTION: This adaptive overcurrent detecting cutout element comprises a pair of electromagnetic poles in the magnetic circuit of a permanent magnet, insulating oil and conductive temperature sensing magnetic substance fine powder between the pair of electromagnetic poles, and an electromagnet having a magnetic circuit partly formed of the pair of electromagnetic poles. The conductive temperature sensing magnetic substance fine powder is as small as approx. 0.2 to 0.3 micron meter which is enough not to lose temperature sensing ferrite magnetism. A gold of approx. 100Åis coated on the surface of the powder. The amount of the conductive temperature sensing magnetic substance fine powder arrested between the pair of electromagnetic poles by the electromagnet is controlled to vary an electric resistance between the pair of electromagnetic poles so as to vary a produced heat quantity in order to change an overcurrent level which leads the temperature to a Curie-point as the result of temperature rising.
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